According to CBS, researchers studied 218,000 people and found that those with the "fat mass and obesity associated" gene did have an increased risk of obesity. But those who exercised for an hour a day, five days a week, had a lower risk than those who were sedentary — 27% lower, to be exact. Study author Dr. Ruth Loos says, "We hope that studies like ours convince people that even when genetically susceptible, a healthy lifestyle will help in the prevention of weight gain."

But Dr. Robert Berkowitz of the Weight and Eating Disorders Program at UPenn points out that the research also shows that people who are obese aren't just slackers:

It really is a genes-environment interaction. Most of us are faced with sedentary jobs, so we're not as active as we used to be even 30 or 40 years ago. I think it all makes it difficult for a person coping with a weight problem.

Not to mention the fact that we're all surrounded by super-addictive junk food!

A growing body of evidence indicates that there's a reason it's so hard for so many…
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We should remember that some vaunted sources of extra weight — like the "freshman 15" and holiday weight gain — are exaggerated. Still, there are pretty clear problems with our cities, our workdays, and our food access that are impacting many people's health. Recent findings on exercise do seem a bit more hopeful than those from years past — another study finds that folks who eat a so-called "high risk" diet rich in meat and low in fruit are better at staving off weight gain if they run regularly. Maybe these studies will inspire employers, city planners, educators, and the government to join forces to make regular physical activity easier for everyone.